1. Field of the Invention
The present invention is related to a security flash memory, data encryption device and method for accessing security memory data, and more particularly to a flash memory with an encryption device and method for accessing data via the encryption device.
2. Description of Related Art
There are many different kinds of memory cards, such as SmartMedia, CompactFlash, MMC and Secure Digital (SD). For the above memory cards, access to data stored therein is very easy as all it requires is a corresponding card reader. Thus, if such a memory card is lost or stolen, confidential data that might be stored therein can easily be accessed by an unauthorized person.
Therefore, methods for protecting contents in the memory card (CPRM, DRM, ACE, or IIS) are disclosed. In the following, the content protection (CPRM, Content Protection for Recordable Media) technology is explained. Through the CPRM technology, the user can achieve personal security of the memory card, such that the data stored in the memory card can be protected, and thus, in the case of loss of the memory card, unauthorized people will not be able to access data stored in the card.
Please refer to FIG. 1, which is a schematic view showing the conventional memory card system with CPRM function. The memory card 1 with CPRM function includes a card body 10, multiple pins 12, a flash memory 14 and a control device 16, wherein multiple pins 12 are mounted at the front end of the card body 10, and the flash memory 14 and the control device 16 are mounted inside the card body 10. The control device 16 is electrically connected with multiple pins 12 and flash memory 14, wherein the control device 16 has a register 162, which has a default value for deciding to enable or disable the CPRM function. When the CPRM function is enabled, the data stored in flash memory 14 can be accessed through the control device 16 in the CPRM manner, and otherwise the data will be accessed through the control device 16 in a general manner.
However, the CPRM technology described above for achieving memory card security still has defects because an unauthorized user of the memory card can easily access the data stored in flash memory 14 by changing the default value stored in register 162 and thus break the CPRM function.